--- libgphoto2-2.4.2/libgphoto2_port/usb/libusb.c.orig	2008-08-27 07:56:33 +0400
+++ libgphoto2-2.4.2/libgphoto2_port/usb/libusb.c	2008-09-22 23:11:42 +0400
@@ -780,6 +780,9 @@
 #endif
 
 	devh = usb_open (dev);
+	/* usb_open can return NULL if device isn't accessible. This is default behaviour for libusb-1 compatibility API */
+	if (!devh) 
+		return 0;
 	/* get string descriptor at 0xEE */
 	ret = usb_get_descriptor (devh, 0x03, 0xee, buf, sizeof(buf));
 	if (ret > 0) gp_log_data("get_MS_OSD",buf, ret);